Cylinder with improved sealing and governor means



Feb. 25, 1964 w. J. CHORKEY 3, 6

CYLINDER WITH IMPROVED SEALING AND GQVERNOR MEANS 2 Sheets-Sheet 1 Filed Feb. 26, 1962 NM QM hm mm 9 E X cm mm INVENTOR. WILLIAM J- CHORKEY BY 2%.W"W

ATTORNEYS W. J. CHORKEY Feb. 25, 1964 CYLINDER WITH IMPROVED SEALING AND GOVERNOR MEANS 2 Sheets-Sheet 2 Filed Feb. 26, 1962 INVENTOR, WILLIAM J-CHORKEY AT TOR NE YS United States Patent 2 Cindi 15. (Cl. 9126) This invention relates generally to power cylinders, and more particularly to a novel and improved sealing and governor means for power cylinders.

It is an important object of the present invention to provide a novel and improved pressure type sealing means for a power cylinder, and in particular for a pressure type sealing means between the cylinder barrel and the barrel ends. The barrel sealing construction is adapted to prevent crushing of the sealing O-ring used as a part of such sealing construction, whereby the O-ring is reusable when the cylinder is taken apart to replace or repair other parts of the cylinder. In the present day power cylinders the sealing means between the barrel ad the barrel ends are put into a pinching condition and when the cylinder is taken apart, the O-rmg seal is not reusable and a new one must be used every time the cylinder is taken apart for repair purposes.

it is another object of the present invention to provide a cushion governor construction which may be incorporated in one or both of the barrel ends and which can be quickly and easily mounted as a corr -act unit the cylinder barrel end members. In the cusl" on governor construction of the present invention the structure thereof is arranged to provide full flow return OL the pressure fluid while providing controlled pressure fluid flow in the forward movement of the cylinder operation. The cushion governor of the present invention is constructed arranged to include a novelly arranged adjustment screw and a ball check valve all within one unit.

It is another object of the present invention to provide novel sealing and cushion governor means for power cylinders which are compact and simple in construction, economical of manufactun, eiiicient in operation and having optimum characteristics of durability and accurac of operation.

Other objects, features and advantages of this invention will be apparent from the following detailed description and appended claims, reference being bad to the accompanying drawings forming a part of the specification wherein like reference numerals designate corresponding parts of the several views.

in the drawings:

FIG. 1 is a top plan view of a cylinder provided with the improved sealing and governor means in accordance the princ les of the present invention;

wiin

1 1G. 2 is an elevational sectional view of the structure illustrated in FIG. 1, taken along the line 22 thereof and looking in the direction of the arrows;

PEG. 3 is an enlarged 'ew of the structure illustrated in FlG. 2 within the circle indicated by the numeral 3; and,

FIG. 4 is a reduced elevational sectional view of the structure illustrated in FIG. 1, taken along the line 4% thereof, looking in the direction of the arrows and with parts removed.

Referring now to the drawings, and in particular to FIGS. 1 and 2, the numeral ill indicates the cylinder barrel which is enclosed at one end thereof with the end cap generally indicated by numeral 11, and at the other end thereof with the gland end cap generally indicated by the numeral 12. Slidably mounted in the cylinder barrel it) is piston generally indicated by the numeral ice 13 to which is operatively connected the piston rod generally indicated by the numeral 14.

As shown in FIGS. 1, 2 and 4, the cylinder end cap 11 comprises a substantially rectangular block which is provided on the inner side thereof with a circular recess 15 and in which is adapted to be seated tie one end of the cylinder barrel 1". As shown in FlGS. 2 and 3, the left end of the barrel it) is provided with a slight undercut on the outer diameter of the barrel, and this undercut portion is adapted to be slidably seated within the circular recess 15. The cylinder barrel 15) is provided with a novel seal construction between the end caps ll and 12, and the seal construction between the barrel 1% and the end cap 11 will first be described.

As shown in FIG. 3, the barrel 3 is provided with an enlarged annular bore in which is adapted to be seated the O-ring 19. The barrel ltl is provided with the i wardly extended bore 1'7 which is provided with the axially extended outer surface 17 which is parallel to the bore 2% of the barrel 19. The bore 28 of the barrel 1? is made to a smaller diameter and the bore 2 is interconnected with the enlarged bore 17 by means of the intermediate bore portion which has the tapered peripheral wall 18. The bore portions 17 and 18 may be termed a cylinder barrel seal recess and the tapered wall portion 18 is preferably formed at a 45 degree angle. The tapered wall 33 which interconnects the axial bores It? and 26 may also be termed a charnfer. The O-ring 19 is adapted to be partially seated on the tapered portion 18 and the axial wall portion 17 under normal conditions, as shown in FIG. 3. As the pressure inside of the cylinder barrel 1o builds up, the O-ring seal 19 is under a slight depression and as the chamber pressure becomes greater than the outside pressure or atmospheric pressure, the seal 19 will tend to try to move outwardly or up the angle surface 18 towards the surface 17. As the seal 19 works its way up the taper or chamfer 1'3 it will provide a pressure sealing efiect because as the pressure increases, the seal 19 tends to become more cornpressed or squeezed into the area bounded by the tapered surface 18, the surface 17 and the bottom surface 21 of the recess 15.

As shown in FIG. 2, the right end of the cylinder barrel 10 is also mounted in the gland end cap 12 in the same manner as the left end thereof is mounted in the end cap lit. The gland end cap 12 is substantially rectangular in cross section, and on the inner side of the body thereof there is formed the annular recess 22 which is formed the same as the annular recess 15 in the end cap 11. The right end of the cylinder barrel 10 is also undercut at the point 23 in the same manner as the other end of the barrel is undercut at the point 16. The right end of the cylinder barrel ill is provided ith the enlarged bore 2 5, and the tapered bore portion 25 similar to the bore portions 17 and 18 on the left end of the cylinder barrel 1%. An O-ring as is seated in the seal chamber formed by the enlarged recess area formed by the bore portions 24 and 25'. The O-ring 26 functions in the same manner as the O-ring 19 on the other or" the cylinder barrel 1Q.

As shown in FIGS. 1 and 2, the end cap :11 and tie gland end cap 12 are detachably secured to the ends of the cylinder barrel 1i) by means of a plurality of tie rods 27 which pass through suitable holes as 23 in the end caps 11 and 3.2, and which are provided with the tie rod nuts 29 on each end thereof.

As shown in FIG. 2, the cylinder of the present ii vention is provided with a piston generally indicated by the numeral 13 which is slidably mounted within the bore 2-9 of the cylinder barrel 10. The piston 13 comprises the body portion 30 which is provided with the spaced apart peripheral grooves 31 and 32 in which are mounted the sealing members 33 and 34. Opera ively mounted in the annular grooves 31 and 32 behind the block V type sealing members 33 and 34 are the circular backup washers 35 and 36, respectively. It will be seen that the tapered portions 18 and 25 of the barrel sealing chambers also function as a guide means to lead the piston sealing members 33 and 34 into the barrel during an assembly operation of the power cylinder. The tapered sealing chamber surfaces 18 and 25 permit the piston to be quickly and easily assembled into the bore 20 of the cylinder barrel 16 in an eflicient manner.

As shown in FIG. 2, the piston rod 14 is provided with the reduced threaded end 37 which is adapted to be seated within the axial hole 38 formed through the piston body 3%. The shoulder 39 on the piston rod abuts the front face of the piston body 30, and the piston lock nut 44 functions to draw the piston rod 14 into tight engagement with the piston body 36. The piston rod 14 has an inner end extension ll which is adapted to extend into the inlet passage 42 in the end cap 11 during movement towards the end cap 11. The outer end of the piston rod 14 is enlarged so as to provide the shoulder 43 at a point which is located a short distance from the front of the piston body 36. A cushion sleeve 44 is mounted around the piston rod 14 between the shoulder 43 on the piston rod and the front face of the piston body 39. A cushion gasket 45 is mounted between the cushion sleeve 44 and the piston body 30. The piston rod 14 extends outwardly through the gland end head 12 and is described in detail hereinafter. An O-ring sealing means 46 is operatively mounted in the reduced piston rod portion 37 to provide sealing engagement with the surface of the hole or bore 38.

As shown in FIGS. 1, 2, and 3, an O-ring sealing means 47 is operatively mounted in the inlet port wall 42. The inlet port 42 is connected to the outer inlet port 43. A circular recess 49 is formed in the upper end of the end cap 11, and threadably mounted therein is the poppet or cushion check assembly generally indicated by the numeral 50. The cushion check assembly chamber 49 is connected by means of the vertical passage 51 with the inlet passage or port 48. The cushion check assembly chamber 49 is also connected to the interior of the cylinder barrel by means of the passageway 52 which is smaller than the inner inlet port 42 and which is disposed above the latter.

The poppet or cushion or check assembly comprises the body portion 53 which is threadably mounted in the upper end of the chamber 49 and which is provided with a hexagonally shaped head that abuts the top of the end cap 11. A suitable O-ring sealing means 54 is operatively mounted between the enlarged hexagonal head of the body 53 and the end cap 11. The cushion check assembly further includes the adjusting screw 55 which is threadably mounted in the axial hole 56 in the body portion 53, and which is secured in adjusted position therein by means of the lock nut 57. The adjusting screw 55 is provided with the cross pin 58 in the outer end thereof. The inner end of the axial hole through the body portion 53 is enlarged, as indicated by the numeral 59, and slidably mounted therewithin is the inner enlarged end 66 of the adjusting screw 55. A suitable O-ring sealing means 61 is operatively mounted on the upper end of the enlarged adjusting screw portion 6% and provides a scaling function between the adjusting screw and the body portion 53.

As shown in FIGS. 2 and 3, a poppet body or valve member 62 is slidably mounted on the lower end of the adjusting screw portion 69. The poppet body 62 is pro vided with the O-ring sealing means 63 which is mounted in the circular recess 64 formed in the bottom end of the poppet body 62. A coiled spring 65 maintains a constant downwardly bias on the poppet body 62 so as to urge the sealing means 63 against the lower face of the chamber 49 so as to surround the passageway 51 and block fiow through the passage 51 and between the chamber 49 and the inlet passage 48. The lower end of the spring 65 engages the upper end of the poppet body 62 and the upper end of the spring 65 is seated in the annular recess 66 formed in the inner end of the body portion 53. A calibrated metered hole or passage 67 is formed through the poppet body 62 and communicates at the inner end thereof with the axial passage 68 in the poppet body 62 and at the outer end thereof with the chamber 49. It will be seen that the adjusting screw 55 may be adjusted inwardly so as to partially block off the calibrated metered hole 67 to control the flow therethrough.

As shown in FIG. 2, the piston rod 14 extends outwardly of the cylinder through the axial passageway or bore 69 which is of a diameter larger than the diameter of the piston rod so as to provide clearance therearound for free flow of pressure fluid. The bore 69 functions in the same manner as the inner inlet port 42 in the end cap 11. A suitable O-ring sealing means 7% is mounted in the gland end cap around the bore 69 adjacent the cylinder side. The gland end cap 12 is provided with a poppet or cushion check assembly 71 which is constructed and mounted in the gland end cap 12 in the same manner as the cushion check assembly 55 is mounted in the end cap 11. Accordingly, the parts of the cushion check assembly 71 have been marked with reference numerals which correspond to the reference numerals for the similar parts of the cushion check assembly 55, followed by the small a.

As shown in FIG. 2, the gland end cap 12 is pro vided with the enlarged circular recess 72 in the outer end thereof which communicates with the axial bore 69. Slidably mounted in the recess 72 is the gland member 73 through which is formed the axial bore 74. The bore 74 is aligned with the bore 69 for passage therethrough of the outer end of the piston rod 14. The gland 73 is held in place in the recess 72 by any suitable means, as by the retaining clip ring 75. The gland 73 carries the block V sealing ring 76 at the inner end thereof and surrounding the piston rod 14 for sealing purposes. A wiper member 77 is carried in the gland '73 at the outer end thereof and in a position surrounding the outer end of the piston rod 14-. The gland 73 is also provided with an O-ring sealing ring 78.

It will be understood that the power cylinder made in accordance with the principles of the present invention may be powered by a pressure fluid which may be either pressurized air or a suitable hydraulic fluid under pressure. In operation, when ,the piston 13 moves to the right as viewed in FIG. 2, the cushion sleeve 44 enters the bore 6? and contacts the O-ring 70 thereby stopping air from exhausting out through the bore 6? and the passage 48a. It will be understood that pressure fluid is entering the cylinder from the other end by means of the passageways 48 and 42 so as to force the piston 13 to the right. The pressure fluid being exhausted from the right hand end of the cylinder bore 26 must then go through the passageway 52a into the chamber 49a and through the small leader hole 67a, in the poppet body 62a. The adjustment screw 55a can be adjusted downwardly over the hole 67a to control the amount of pressure fluid passing therethrough, thereby forming a cushion of pressure fluid against which the piston 13 will be seated. The pressure fluid will escape from the right end of the cylinder bore 24} in accordance with the setting of the adjustment needle 55a.

When the piston 13 is all the way over to the right hand end of the cylinder, as viewed in FIG. 2, the direc tion of flow of the pressure of fluid is reversed by suitable exterior control valves. The pressure fluid to the left of the piston 13 would be adjusted out through the passageways 42 and 28, and the incoming pressure fluid being admitted to the right end of the cylinder will be admitted through the passageway 48a and the passage let up against the lower end of the poppet body 62a The poppet body 62a is moved upwardly against the pressure of the spring 65a and free flow of pressure fluid may take place into the right end of the cylinder through the passageway 52a. The piston 13 is thus moved to the left, as viewed in FIG. 2, and as the piston 13 moves to the left, the sleeve 44 will be drawn out of the bore 69 to permit flow of the pressure fluid directly from the passage 48 and the bore 69 into the interior of the cylinder 10. When the piston 13 approaches the left end of the cylinder, as viewed in FIG. 2, the cylinder rod projection 41 will move into the passageway 42 and engage the seal 47 so as to stop passage of the pressure fluid out of the port 42. The remaining pressure fluid will Chen be exhausted through the passage 52 and the small metered hole 67 in the passageways 51 and 48 so as to provide a pressure fluid cushion at the left end of the cylinder. When a piston 13 is to be moved to the right again, it will be seen that pressure fluid entering the passages 48 and 51 will move the poppet body 62 upwardly so as to permit full fiow of the fluid through the passage 52 and into the interior of the cylinder barrel 10.

it has been found that the pressure seal means 19 and 26 function with the tapered surfaces 18 and 25 so as to increase the sealing efficiency when the pressure in the cylinder is increased. Furthermore, the undercut portion of the cylinder barrel at the ends thereof, namely the portions 16 and 23, provide a construction whereby the end caps 11 and 12 are seated directly against the end of the cylinder barrels, thus simplifying the pre-stressing of the tie rods 27 and eliminating binding due to uneven tightening of the tie rods. The last mentioned construction also provides leakproof seals between the end caps and the barrel because pressure surges inside of the cylinder barrel cannot increase the metal clearance between the end caps and the barrel because the barrel is piloted on the outside thereof. Initial seal compression of the O-rings 19 and as is controlled by the tapered shoulders 18 and 25 and the barrel end shoulders formed by the enlarged bore portion 17 and 23, whereby crushing of the O-rings 19 and 2-5 during assembly is impossible. It will be seen that although one metered hole as 67 is shown in each of th poppet bodies (2, a number of such holes or passages may be provided as desired. It will also be noted that each end of the piston is tapered as indicated at the numeral 78, on the periphery thereof, to permit a large effective initial operating area for the pressure fluid being admitted to the cylinder for reversing and starting operations. ltvwill be understood that the cushion governors may be provided on each end of the cylinder, as shown in the drawings, or on only one end of the cylinder in accordance with the job to which the cylinder is to be used.

While it will be apparent that the preferred embodiments of the invention herein disclosed are well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What I claim is:

1. In a power cylinder, the combination, comprising:

(a) a cylinder barrel having an end cap mounted on one end thereof and a gland end cap mounted on the other end thereof,

(b) each of said end caps having a pressure fluid passageway formed therethrough for admitting fluid into, and exhausting fluid from, each end of to cylinder barrel,

(0) each of the passageways in the end caps including an outer port for connection to a source of pressure fluid, an inner port communicating at one end with the outer port and at the other end with the interior of said cylinder barrel, a chamber, a

first passage connecting said chamber and outer port, and a second passage connecting said chamber and the interior of said cylinder barrel,

(d) a piston operatively mounted in said cylinder and having a piston rod connected thereto and ex tended outwardly through said gland end cap,

(e) a pressure seal means mounted at each end of the cylinder barrel to provide a seal between the cylinder bar-rel and each end cap,

(f) means on said piston rod engageable with the inner ports in the end caps at each end of the stroke of the piston for blocking flow of pressure fluid therethrough,

(g) a cushion governor means mounted in at least one of said end cap fluid passageways, in the chamber thereof, for controlling the exhaust rate of flow of fluid from the interior of the cylinder barrel through a flow system including the first and second passages, the chamber and the outer port of said last named fluid passageway,

( said cushion governor means including a body portion mounted in the respective chamber, and adjusting screw adjustably mounted in said body portion, a poppet valve slidably mounted on the inner end of the adjusting screw and normally closing one end of the first passage connected to the respective chamber, spring means for normally biasing said poppet valve to its closing position, a metered passage formed through said poppet valve and cornmunicating the respective chamber and connecting first passage, and said adjusting screw being adapted to regulate the amount of fluid flowing through said metered passage when the poppet valve is in'the closed position.

2. In a power cylinder, the combination, comprising:

(a) a cylinder barrel having an end cap mounted on one end thereof and a gland end cap mounted on the other end thereof,

(h) each of said end caps having a pressure fluid passageway formed therethrough for admitting fluid into, and exhausting fluid from, each end of the cylinder barrel,

(0) each of the passageways in the end caps including an outer port for connection to a source of pressure fluid, an inner port communicating at one end with the outer port and at the other end wit the interior of said cylinder barrel, a chamber, a first passage connecting said chamber and outer port, and a second passage connecting said chamber and the int rior of said cylinder barrel,

((1) a piston operatively mounted in said cylinder and having a piston rod connected thereto and extended outwardly through said gland end cap.

(e) means on said piston rod engageable with the inner ports in the end caps at each end of the stroke of the piston for blocking flow of pressure fluid therethrough,

(f) a cushion governor means mounted in at least one of said end cap fluid passageways, in the chamber thereof, for controlling the exhaust rate of flow of fluid from the interior of the cylinder barrel through a flow system including the first and second passages, the chamber and the outer port of said last named fluid passageway,

(g) each of the end caps having a circular recess formed on the inner side thereof in which is slidably mounted the adjacent end of the cylinder barrel,

(h) the interior at each end of the cylinder bmrel being enlarged to form a sealing ring chamber and having an outwardly sloping wall portion,

(i) a sealing ring mounted in each of the sealing ring chambers and engaging said sloping wall portion and the inner end wall of said recess, and

(3) said cushion governor means including a body portion mounted in the respective chamber, an adjust ng screw adjustably mounted in said body portion, a poppet valve slidably mounted on the inner end of the adjusting screw and normally closing one end of the firsttpassage connected to the respective chamber, spring means for normally biasing said poppet valve to its closing position, a metered passage formed through said poppet valve and communicating the respective chamber and connecting first passage, and said adjusting screw being adapted to regulate the amount of fluid flowing through said metered passage when the poppet valve is in the closed position.

References Cited in the file of this patent UNITED STATES PATENTS 2,755,775 Flick et al. July 24, 1956 2,833,312 Flick May 6, 1958 2,842,284 Flick July 8, 1958 2,967,744 Davies Jan. 10, 1961 

1. IN A POWER CYLINDER, THE COMBINATION, COMPRISING: (A) A CYLINDER BARREL HAVING AN END CAP MOUNTED ON ONE END THEREOF AND A GLAND END CAP MOUNTED ON THE OTHER END THEREOF, (B) EACH OF SAID END CAPS HAVING A PRESSURE FLUID PASSAGEWAY FORMED THERETHROUGH FOR ADMITTING FLUID INTO, AND EXHAUSTING FLUID FROM, EACH END OF THE CYLINDER BARREL, (C) EACH OF THE PASSAGEWAYS IN THE END CAPS INCLUDING AN OUTER PORT FOR CONNECTION TO A SOURCE OF PRESSURE FLUID, AN INNER PORT COMMUNICATING AT ONE END WITH THE OUTER PORT AND AT THE OTHER END WITH THE INTERIOR OF SAID CYLINDER BARREL, A CHAMBER, A FIRST PASSAGE CONNECTING SAID CHAMBER AND OUTER PORT, AND A SECOND PASSAGE CONNECTING SAID CHAMBER AND THE INTERIOR OF SAID CYLINDER BARREL, (D) A PISTON OPERATIVELY MOUNTED IN SAID CYLINDER AND HAVING A PISTON ROD CONNECTED THERETO AND EXTENDED OUTWARDLY THROUGH SAID GLAND END CAP, (E) A PRESSURE SEAL MEANS MOUNTED AT EACH END OF THE CYLINDER BARREL TO PROVIDE A SEAL BETWEEN THE CYLINDER BARREL AND EACH END CAP, (F) MEANS ON SAID PISTON ROD ENGAGEABLE WITH THE INNER PORTS IN THE END CAPS AT EACH END OF THE STROKE OF THE PISTON FOR BLOCKING FLOW OF PRESSURE FLUID THERETHROUGH, (G) A CUSHION GOVERNOR MEANS MOUNTED IN AT LEAST ONE OF SAID END CAP FLUID PASSAGEWAYS, IN THE CHAMBER THEREOF, FOR CONTROLLING THE EXHAUST RATE OF FLOW OF FLUID FROM THE INTERIOR OF THE CYLINDER BARREL THROUGH A FLOW SYSTEM INCLUDING THE FIRST AND SECOND PASSAGES, THE CHAMBER AND THE OUTER PORT OF SAID LAST NAMED FLUID PASSAGEWAY, (H) SAID CUSHION GOVERNOR MEANS INCLUDING A BODY PORTION MOUNTED IN THE RESPECTIVE CHAMBER, AND ADJUSTING SCREW ADJUSTABLY MOUNTED IN SAID BODY PORTION, A POPPET VALVE SLIDABLY MOUNTED ON THE INNER END OF THE ADJUSTING SCREW AND NORMALLY CLOSING ONE END OF THE FIRST PASSAGE CONNECTED TO THE RESPECTIVE CHAMBER, SPRING MEANS FOR NORMALLY BIASING SAID POPPET VALVE TO ITS CLOSING POSITION, A METERED PASSAGE FORMED THROUGH SAID POPPET VALVE AND COMMUNICATING THE RESPECTIVE CHAMBER AND CONNECTING FIRST PASSAGE, AND SAID ADJUSTING SCREW BEING ADAPTED TO REGULATE THE AMOUNT OF FLUID FLOWING THROUGH SAID METERED PASSAGE WHEN THE POPPET VALVE IS IN THE CLOSED POSITION. 